Columbia-Class: Key Design Features
Design Features
| Class overview | |
|---|---|
| Preceded by: | Ohio class |
| Cost: | $109.8 billion for 12 boats (FY2021, projected) |
| Planned: | 12 |
| Specs | |
| Type: | Ballistic missile submarine (SSBN) |
| Displacement: | 20,810 long tons (submerged) |
| Length: | 560 ft (171 m) |
| Beam: | 43 ft (13 m) |
| Speed: | 20+ knots |
| Diving Depth: | 800+ feet |
| Installed power: | Nuclear reactor |
| Propulsion: | Turbo-electric drive, pump-jet |
| Range: | Unlimited |
| Complement: | 155 (accommodation) |
| Sensors and processing systems: | Enlarged version of the Virginia-class LAB sonar |
| Armament: | 16 × Trident D5 |
General Characteristics
Although still evolving, the following are some of the characteristics for the SSBN(X) design:
- Expected 42-year service life (each submarine is expected to carry out 124 deterrent patrols during its service life)
- Life-of-the-ship nuclear fuel core that is sufficient to power the submarine for its entire expected service life, unlike the Ohio-class submarines, which require a mid-life nuclear refueling
- Missile launch tubes that are the same size as those of the Ohio class, with a diameter of 87 inches (2,200 mm) and a length sufficient to accommodate a D-5 Trident II missile
- 16 missile launch tubes instead of 24 missile launch tubes on Ohio-class submarines.
- Beam at least as great as the 42-foot (13 m) beam of the Ohio-class submarines
- Submerged displacement about the same as that of Ohio-class submarines
Advanced Capabilities
The U.S. Navy has also stated that "owing to the unique demands of strategic relevance, SSBN(X)s must be fitted with the most up-to-date capabilities and stealth to ensure they are survivable throughout their full 40-year life span."
Additional reported design features include:
- X-shaped Stern Control Surfaces (hydroplanes)
- Sail-mounted Dive Planes
- Integrated Power System (IPS) and Nuclear Reactor
- Nuclear Electric Drive
- Pump-jet Propulsor
- Anechoic Coating
- Large Aperture Bow (LAB) sonar system
- Stern Area System (SAS)
Note the offset axis of the X-rudder planes, with alternating rudders slightly more forward.
GDEB image of the stern section of the USS District of Columbia (SSBN-826).
Common Missile Compartment (CMC)
As part of the US strategic nuclear deterrence plan, Columbia class SSBNs and the Royal Navy’s Dreadnought Class of SSBNs will carry the Trident II D-5 missile for the first portion of their respective operational lives. Since 2008, the United States and the United Kingdom (U.K.) have been jointly developing a common system to house the tubes that will carry these submarine launched ballistic missiles. Each Common Missile Compartment (CMC) will will hold four missle tubes, and is therefore often called a "Quad-Pack". The Columbia class will hold four Quad-Packs (16 tubes) and the Dreadnought Class will use three Quad-Packs. The U.S. missiles are armed with nuclear warheads maintained by the Department of Energy (DOE).
In addition to the missile tubes, the CMC program also provides systems to support the missiles and the launch equipment, including power, cooling,
gas venting, and launch hardware and software. The Navy’s Strategic Systems Program is responsible for CMC development efforts.
Workers stand in the four tube "Quad-Pack" built as part of the CMC Program. (GDEB Photo via US Navy)
Columbia-Class Submarine Size
Columbia-Class Submarines will be the largest U.S. Navy Submarine ever built.
It will be larger than the Ohio-class, the current largest submarine, in terms of submerged displacement.
